Improvement in balance-valves for steam-engines



UNITE@ STATES armar rines.

JOHN W. OARHART, OF TROY, NEW YORK.

IMPROVEMENT IN BALANCE-VALVES FOR STEAM-ENGINES.

Specification forming part of Letters Patent No. 53,410, dated March 27,1866.

To all whom it may concern:

Beit known that l, J. WESLEY UARHART, ot' Troy, in the county ofRensselaer and State of New York, have invented a new and ImprovedSteam-Valve 5 and I do hereby declare that the following is a full,clear, and exact description thereof, which will enable those skilled inthe art to make and use the same, reference being had to accompanyingdrawings, forming part ot' this specication, in which- Figure lrepresents a horizontal section of this invention in the line w fr, Fig.2 indicating the plane of section. Fig. 2 is an end View of the same.Fig. 3 is a vertical central section of the same, the line yy, Fig. 2,indicating the plane of section. Fig. 4 is a transverse vertical sectionot the same, taken in the plane indicated by the line z z, Fig. l. Fig.5 is a transverse vertical section of the plug detached, the plane ofsection being indicated by the line w x', Fig. 3. Fig. 6 is an end viewof the plug detached.

Similar letters of reference indicate corresponding parts.

This invention relates to certain improvements in that class of valveson which patents have been granted to me November 29, 1864, and July 25,1865.

The improvements which form the subjectmatter ot' this present inventionconsists, first, inarecess in the upper portion of the thin end of theplug, said recess being made to communicate with the steam-space of thevalve in such a manner that the valve is equally balanced at its thinend as well as at its thick end, second, in the application of a yokeover the thick end of the valve, in combination with a screwextendingfrom the shank or end of the valve and provided with suitablenuts, in such a manner that the valve can be adjusted and kept tightwithout removing the head ofthe shell; third, in the application of aset-screw in the thin end of the shell and bearing on a cross-bar in thethin end ot' the valve in such a manner that the position of the valvein the shell can be adjusted at pleasure 5 fourth, in placing the plugbetween two adjustable centers in such a manner that its position in theshell can be adjusted with the greatest accuracy, and all unnecessaryfriction can be avoided.

A represents a plug, made ot' brass, iron, or any other suitablematerial, and fitted into -a shell, B, as shown in Figs. l and 3, of thedrawings. The plug is conical and itis bored out from its thin end so asto form a cavity, a, from which a channel, b, extends through the sideof the plug, as shown in Figs. 3 and 4. By turning the plug so that thechannel b coincides with one of the ports c c in the bottom plate of theshell B, the steam which euters through a hole in the small head of theshell into the cavity a in the plug has access to either end of thecylinder, and by turning the plug the steam is changed. rlhecommunication between the exhaust-pipe d in the shell and the ports c c'is etected by a recess, e, in the central part of the plug, andoccupying an arc ot' three hundred degrees, more or less, as seen inFig. 4.

If the valve is turned so that the channel b coincides with the port o,the port c communicates through the recess e with exhaust-pipe d, and byreversing the valve the steam is admitted through the port c', and itexhausts through the port c.

IThe recess c is situated between the collars or projectionsff, one atthe large end ot' the plug and one at its small end, and in order tobalance the upward pressure of the steam on the large end, theprojection or collar j'/ is provided with a recess, g, whichcommunicates through holes h with the cavity or steam-space a, asdescribed in my Patent No. 48,902, dated July 25, 1865.

In the same manner I have also balanced the thin end of the plug by arecess, t', in the collarf, said recess being made to communicate withthe steam -space d through small holes j. From the large end of the plugextends a stem, 7o, through a stuffing-box, l, in the head D, whichcloses the large end of the shell, and from the end of this stem extendsa screw, m, through a yoke, a, which is tirmly secured to the head D, asshown in the drawings.

Nuts o, fitted on the screw m and placed on the inside and outside ofthe yoke, serve to adjust the plug in the desired position, and suitablejam-nuts p prevent the nuts o from unscrewing spontaneously. v

The thin end of the shell B is provided with a cross-bar, q, which istapped to receive the set'screw r. The pointed end of this set-screw 2.The arrangement of the screw m, yoken, bears on a crossbar, s, securedin the thin end set-screw r, and cross-bar q with the plugof the valve,as shown in Fig. 3, and by the valveAand shell B,constructed andoperating action of this set-screw the thin end of the substantially asand for the purpose set forth. valve is held. in position. The abovespecification of my invention What I claim as new, and desire to securesigned by me this 3d day of October, 1865. by Letters Patent, s-

1. The recess t' in the thin end of the plug- Witnesses: valve A,constructed and operating substantiaily as and for the purposedescribed.

J. WESLEY GARHART.

M. M. LrVINGsToN, 0. D. MUNN.

